The 6.0-magnitude quake rocked the main tourist district of Kuta for several minutes, said Endro Tjahjono from the Bali office of Indonesia’s Meteorology and Geophysics Agency.
“There was panic — everyone ran out of the buildings. When we returned to our office building, we saw some cracks on the wall and plaster had come off the walls,” he told AFP.
Kuta’s Sunset Road was hit hard, with hundreds of tourists fleeing from malls, restaurants and supermarkets.
“Hundreds of people ran onto the streets. It was chaos. So many people tried to drive off that the traffic came to a standstill,” said Reno Permana, who works for a mobile phone service and ran from the third floor of his office building when the quake hit.
“Part of the wall on the Carrefour supermarket near my building came down, and tiles from the roof fell and smashed into the parking lot. A lot of the buildings are badly damaged, with windows smashed in.”
Indonesia sits on the Pacific “Ring of Fire”, where the meeting of continental plates causes high seismic activity, and is frequently hit by earthquakes.
In October 2010 a powerful earthquake triggered a huge tsunami off the coast of Sumatra, northwest of Bali, that killed at least 300 people.
The US Geological Survey (USGS) said the epicentre of Thursday’s quake was in the ocean near the resort of Nusa Dua, south of Bali’s capital Denpasar. But the Hawaii-based Pacific Tsunami Warning Center said there was no current tsunami warning in effect.
Nusa Dua has suffered little damage, hotel operators said.
Indonesian National Disaster Management Agency spokesman Sutopo Purwo Nugroho said 17 people suffered light injuries from falling roof tiles in the quake, and a hospital, three schools and two government buildings were damaged.
But Ken Wirasandhi, a doctor from Sanglah hospital, said 44 people, mostly students, were treated for cuts and head wounds.
“Two students are still under observation. They suffered head wounds when roof tiles crashed on them. The others received outpatient treatment for cuts and have gone home,” he told AFP.
Over a dozen students — their uniforms torn and blood-stained — were crying and clutching their bleeding heads at the hospital.
“We panicked and ran out of our classroom, but something fell on us when we were running outside,” high-school student Valentina said.
Hundreds of terrified tourists on Kuta’s beach strip raced from their hotels, officials and hotel staff said.
“It was a chaotic scene. Tourists dashed out of their hotels to the roads screaming ‘Quake! Quake!’,” Bali Hotels and Restaurant Association secretary general Perry Markus said.
Stephanie Fleming, a Briton who works for a tourism company in the Seminyak area close to Kuta, said her office shook violently for around a minute.
“It happened so quickly. Everything was shaking and the doors were banging open and shut. We didn’t really know what to do so we all ran out onto the street,” she said.
“It looked like a wall in our office was about to fall down, but all the structures outside seem more or less intact.”
The epicentre was measured at 61.3 kilometres (38.1 miles) deep, some 130 kilometres south-southwest of Denpasar, said US seismologists, who measured its magnitude at 6.0.
Indonesia’s Meteorology and Geophysics Agency measured the magnitude of the undersea quake at 6.8 and put its depth at just 10 kilometres, but also said it was unlikely to cause a tsunami.
The quake was also felt in neighbouring areas such as Surabaya, Blitar and Malang cities in east Java.